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Subject: Science, asked on on 3/8/14

Could anyone explain the meaning of these lines:Transmission of Nerve Impulse The transmission of a nerve impulse along a neuron from one end to the other occurs as a result of electrical changes across the membrane of the neuron. The membrane of an unstimulated neuron is polarized—that is, there is a difference in electrical charge between the outside and inside of the membrane. The inside is negative with respect to the outside. Polarization is established by maintaining an excess of sodium ions (Na+) on the outside and an excess of potassium ions (K+) on the inside. A certain amount of Na+ and K+ is always leaking across the membrane through leakage channels, but Na+/K+ pumps in the membrane actively restore the ions to the appropriate side. The main contribution to the resting membrane potential (a polarized nerve) is the difference in permeability of the resting membrane to potassium ions versus sodium ions. The resting membrane is much more permeable to potassium ions than to sodium ions resulting in slightly more net potassium ion diffusion (from the inside of the neuron to the outside) than sodium ion diffusion (from the outside of the neuron to the inside) causing the slight difference in polarity right along the membrane of the axon.Other ions, such as large, negatively charged proteins and nucleic acids, reside within the cell. It is these large, negatively charged ions that contribute to the overall negative charge on the inside of the cell membrane as compared to the outside. In addition to crossing the membrane through leakage channels, ions may cross through gated channels. Gated channels open in response to neurotransmitters, changes in membrane potential, or other stimuli. The following events characterize the transmission of a nerve impulse: Resting potential. The resting potential describes the unstimulated, polarized state of a neuron (at about 70 millivolts). Graded potential. A graded potential is a change in the resting potential of the plasma membrane in the response to a stimulus. A graded potential occurs when the stimulus causes Na+ or K+ gated channels to open. If Na+ channels open, positive sodium ions enter, and the membrane depolarizes (becomes more positive). If the stimulus opens K+ channels, then positive potassium ions exit across the membrane and the membrane hyperpolarizes (becomes more negative). A graded potential is a local event that does not travel far from its origin. Graded potentials occur in cell bodies and dendrites. Light, heat,15mechanical pressure, and chemicals, such as neurotransmitters, are examples of stimuli that may generate a graded potential (depending upon the neuron). The following four steps describe the initiation of an impulse to the resetting of a neuron to prepare for a second stimulation: 1. Action potential. Unlike a graded potential, an action potential is capable of traveling long distances. If a depolarizing graded potential is sufficiently large, Na+ channels in the trigger zone open. In response, Na+ on the outside of the membrane becomes depolarized (as in a graded potential). If the stimulus is strong enough—that is, if it is above a certain threshold level—additional Na+ gates open, increasing the flow of Na+ even more, causing an action potential, or complete depolarization (from 70 to about +30 millivolts). This in turn stimulates neighboring Na+ gates, farther down the axon, to open. In this manner, the action potential travels down the length of the axon as opened Na+ gates stimulate neighboring Na+ gates to open. The action potential is an all-or-nothing event: When the stimulus fails to produce depolarization that exceeds the threshold value, no action potential results, but when threshold potential is exceeded, complete depolarization occurs. 2. Repolarization. In response to the inflow of Na+, K+ channels open, this time allowing K+ on the inside to rush out of the cell. The movement of K+ out of the cell causes repolarization by restoring the original membrane polarization. Unlike the resting potential, however, in repolarization the K+ are on the outside and the Na+ are on the inside. Soon after the K+ gates open, the Na+ gates close. Hyperpolarization. By the time the K+ channels close, more K+ have moved out of the cell than is actually necessary to establish the original polarized potential. Thus, the membrane becomes hyperpolarized (about 80 millivolts). 3. Refractory period. With the passage of the action potential, the cell membrane is in an unusual state of affairs. The membrane is polarized, but the Na+ and K+ are on the wrong sides of the membrane. During this refractory period, the axon will not respond to a new stimulus. To reestablish the original distribution of these ions, the Na+ and K+ are returned to their resting potential location by Na+/K+ pumps in the cell membrane. Once these ions are completely returned to their resting potential location, the neuron is ready for another stimulus.

Mohammed Ghufran asked a question
Subject: Science, asked on on 10/6/10
Sweta Mishra & 7 others asked a question
Subject: Science, asked on on 17/5/14

See importance of lokpal bill and forward it:

Summary of All scams of India : Rs. 910603234300000/-FunFunky.com

See how Lokpal Bill can curb the politicians, Circulate it to create awareness

Existing System

System Proposed by civil society

No politician or senior officer ever goes to jail despite huge evidence because Anti Corruption Branch (ACB) and CBI directly come under the government. Before starting investigation or prosecution in any case, they have to take permission from the same bosses, against whom the case has to be investigated.

Lokpal at centre and Lokayukta at state level will be independent bodies. ACB and CBI will be merged into these bodies. They will have power to initiate investigations and prosecution against any officer or politician without needing anyone’s permission. Investigation should be completed within 1 year and trial to get over in next 1 year. Within two years, the corrupt should go to jail.

No corrupt officer is dismissed from the job because Central Vigilance Commission, which is supposed to dismiss corrupt officers, is only an advisory body. Whenever it advises government to dismiss any senior corrupt officer, its advice is never implemented.

Lokpal and Lokayukta will have complete powers to order dismissal of a corrupt officer. CVC and all departmental vigilance will be merged into Lokpal and state vigilance will be merged into Lokayukta.

No action is taken against corrupt judges because permission is required from the Chief Justice of India to even register an FIR against corrupt judges.

Lokpal & Lokayukta shall have powers to investigate and prosecute any judge without needing anyone’s permission.

Nowhere to go - People expose corruption but no action is taken on their complaints.

Lokpal & Lokayukta will have to enquire into and hear every complaint.

There is so much corruption within CBI and vigilance departments. Their functioning is so secret that it encourages corruption within these agencies.  

All investigations in Lokpal & Lokayukta shall be transparent. After completion of investigation, all case records shall be open to public.  Complaint against any staff of Lokpal & Lokayukta shall be enquired and punishment announced within two months.

Weak and corrupt people are appointed as heads of anti-corruption agencies.

Politicians will have absolutely no say in selections of Chairperson and members of Lokpal & Lokayukta. Selections will take place through a transparent and public participatory process.

Citizens face harassment in government offices. Sometimes they are forced to pay bribes. One can only complaint to senior officers. No action is taken on complaints because senior officers also get their cut.

Lokpal & Lokayukta will get public grievances resolved in time bound manner, impose a penalty of Rs 250 per day of delay to be deducted from the salary of guilty officer and award that amount as compensation to the aggrieved citizen.

Nothing in law to recover ill gotten wealth. A corrupt person can come out of jail and enjoy that money.

Loss caused to the government due to corruption will be recovered from all accused.

Small punishment for corruption- Punishment for corruption is minimum 6 months and maximum 7 years.

Enhanced punishment - The punishment would be minimum 5 years and maximum of life imprisonment.

Dear All, Please go through the details carefully & try to be part of this mission against corruption. Things to know about Anna Hazare and Lok pal Bill-:  

1.Who is Anna Hazare?

An ex-army man(Unmarried). Fought 1965 Indo-Pak war.

 

2.What's so special about him?

He built a village Ralegaon Siddhi in Ahamad Nagar district, Maharashtra.

 

3.This village is a self-sustained model village. Energy is produced in the village itself from solar power, biofuel and wind mills. In 1975, it used to be a poverty clad village. Now it is one of the richest village in India. It has become a model for self-sustained, eco-friendly & harmonic village.

4. This guy, Anna Hazare was awarded Padma Bhushan and is a known figure for his social activities.

 

5. He is supporting a cause, the amendment of a law to curb corruption in India.

 

6. How that can be possible?

He is advocating for a Bill, The Lok Pal Bill (The Citizen Ombudsman Bill), that will form an autonomous authority who will make politicians (ministers), bureaucrats (IAS/IPS) accountable for their deeds. 

 

7. It's an entirely new thing right..?

In 1972, the bill was proposed by then Law minister Mr. Shanti Bhushan. Since then it has been neglected by the politicians and some are trying to change the bill to suit their theft (corruption).

 

8. Oh.. He is going on a hunger strike for that whole thing of passing a Bill ! How can that be possible in such a short span of time? The first thing he is asking for is: the govt should come forward and announce that the bill is going to be passed. Next, they make a joint committee to DRAFT the LOK PAL BILL. 50% government participation and 50% public participation. Bcoz u can't trust the government entirely for making such a bill which does not suit them.

 

9.What will happen when this bill is passed?

A LokPal will be appointed at the centre. He will have an autonomous charge, say like the Election Commission of India. In each and every state, Lokayukta will be appointed. The job is to bring all alleged party to trial in case of corruptions within 1 year. Within 2 years, the guilty will be punished. 

10. Do you know The R.T.I. bill Prepare and imposed by ANNA in Maharastra.   

 

Pass this on n show ur support..

 

Spread it like   fire; Our Nation needs us... Please Contribute... This is not just a forward, it’s the future of our Nation

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